As a general rule, an equipment front face includes a top cross-member for interfacing with a hood which is secured thereto by means of at least one lock housed in the cross-member.
The top cross-member performs several functions:                firstly it must prevent the hood from opening in undesired manner, whether when forced as a result of vandalism, or accidentally under the effect of suction applied to the hood while the vehicle is running or following a front impact;        secondly it must enable the hood to be slammed shut, i.e. it must enable it to be closed after dropping through several tens of centimeters;        thirdly it contributes to stiffening the body of the vehicle since it provides a transverse connection between its fenders; and        fourthly, in some cases, it must be capable of supporting functional members of the vehicle, such as a radiator.        
In order to perform these functions, the cross-member must be sufficiently stiff. In particular it must present good bending strength, and also (although to a lesser extent) good twisting strength.
Such a cross-member is extended at its ends:                firstly by lateral supports, onto which various functional members of the vehicle are generally fixed, such as headlights, and whereby the cross-member is connected to a fender skirt or to an upper side rail; and        secondly by legs which connect the top cross-member to bottom plates for fixing the front faces of the side rails, and on which a bumper beam is generally fixed.        
The plates form the main anchor points of the equipment front face, while the ends of the side supports form secondary anchor points. It is therefore preferable for the legs and the side supports also to present good stiffness, and in particular good bending strength.
Equipment front faces are known that are made essentially out of metal.
Although such front faces are quite good at withstanding the bending stresses that result from traction exerted on the hood in order to force it open, they are nevertheless complicated to manufacture, since manufacture requires numerous operations, in particular cutting-out operations, stamping operations, and welding operations which are complex and require large and expensive tooling. In addition, such front faces are relatively heavy. However, car manufacturers are seeking on the contrary to lighten the structural parts of vehicles.
Other types of equipment front face also exist that are made essentially out of plastics material.
Such front faces are more convenient to manufacture, since injecting plastics material is by its very nature more flexible than is shaping metals.
Nevertheless, those plastics materials that have the highest performance (specifically in terms of bending strength) are also the most expensive.
In addition, for given strength, a part made of plastics material is generally bulkier than a part made of metal.
Although manufacturers are seeking lightness as mentioned above, they are also seeking compactness.